1). Building and being part of the team that launched GOV.UK - from a blank sheet of paper through to 1 billion visits and a £60m saving for UK tax payers each year. I had so much fun disrupting the status quo, helping to establish an agile service delivery culture across government. Agile is now the new normal for service delivery in government and that's a little bit to do with starting the alpha version of GOV.UK, forming an incredible team that showed the art of the possible and which exemplified a culture of delivery.

2). I'm proud of the part I played helping reset Universal Credit, the UK's welfare reform programme. It's a sensible policy, with cross-party buy-in but it was in a bit of pickle in 2012/13. I helped form the cross departmental, multi-disciplinary team that will deliver a future welfare system, designed to be fairer, a little more human, a lot more agile and responsive to feedback from users. That's totally a win for the Civil Service and the UK - against many odds.

3). Getting to work on briefs like this - and I'm paraphrasing: "Imagine it's 10 years from now... Without messing with democracy ('cos we like that), how would you build a natively digital state ('cos the current system is mostly 19th Century!) and make services so simple..?". Such fun was had, working with some of the most incredible minds. I learned so much and once seen it cannot be unseen.

4). At times I was shocked at the sheer bonkers-ness of it all but also there were many moments of awe. Seeing the system of government up close was fascinating and never again will the news headlines read the same. There's things I'd change but there is a lot to be thankful about our system of government and its administration. I loved walking into my local pub and playing up the jibes about paperclips and civil servants, but the truth is it is packed with talented, public spirited, hard working people. Properly talented. We are lucky people, us Britishers.